Cooperation among Muslim groups

Question: “Allah (Exalted be He) says:{Help you one another in Al-Birr and At-Taqwâ (virtue, righteousness and piety); but do not help one another in sin and transgression.} [Surah al-Ma’idah 5:2] It is said that based on this Ayah (Qur'anic verse), Muslims have to cooperate with all the Islamic groups, even if they differ among themselves in the Manhaj (methodology) and way of Da`wah (calling to Islam). Tabligh (a group calling to Islam) for example adopts a method of Da`wah different from that adopted by the Muslim Brotherhood, Hizb Al-Tahrir, Al-Jihad Group and Salafiyyah (those following the way of the righteous predecessors). What is the criterion governing cooperation with all the Islamic groups? Can it be limited to attending conferences and seminars? What if non-Muslims are invited to enter Islam? This may be the cause of huge confusion to new converts, since each group will invite them to its centers to listen to its scholars and they may be confused. How can this problem be avoided?”Answer: “It is your duty to cooperate with the group adopting the Manhaj of the Qur'an, Sunnah (whatever is reported from the Prophet) and the Salaf (righteous predecessors) in inviting people to witness to the Oneness of Allah and worship Him Alone while warning them against Shirk (associating others with Allah in His Divinity or worship), Bid`ahs (innovations in religion), and sins. After that, you should advise the groups deviating from that Manhaj and if they return to the truth, you can cooperate with them, but if they insist on their disagreement, you should stay away from them and adhere to the Qur'an and Sunnah. Cooperating with the group sticking to the Book of Allah and Sunnah can be in every good, righteous and virtuous way. It can be by attending seminars, conferences, sermons and lectures, in addition to participating in anything that benefits Islam and Muslims. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.”The Permanent Committee for Scholarly Research and Ifta'Shaykh 'Abdul-'Azeez bin 'Abdullaah bin BaazShaykh 'Abdul-'Azeez Aal ash-ShaykhShaykh ‘Abdullah al-GhudayyaanShaykh Saalih al-FawzaanShaykh Bakr Abu Zayd